MGH PM - Gastroenterology III Flashcards
Nutrition in hospitalized patients - Pathophysiology:
- When acutely ill, catabolism > anabolism ==> Carbs preferred due to decr. fat metab.
- When recovering, anabolism > catabolism ==> Body restores protein and muscle loss.
Nutrition in hospitalized patients - Critical illness (JPEN 2009):
Goals not well validated but 18-30 kcal/kg/d and 1.2-1.5g/kg/d protein.
Nutrition in hospitalized patients - Critical illness - Enteral:
Start w/in 24-48hrs of admission, trend toward decr. infxns and mortality in early (<48h) feeding in critically ill Pts who are adequately nourished at presentation.
Nutrition in hospitalized patients - Critical illness - Enteral - Contraindic:
- Inadequate volume resusc.
- Intestinal obstruction.
- Major GIB.
- Severe vomiting.
- Ischemic bowel.
Nutrition in hospitalized patients - Critical illness - Parenteral:
Start if unable to tolerate enteral w/in 7d or evidence of protein/cal malnutrition on admission.
==> May be beneficial in those below calorie goal w/ enteral (Lancet 2013).
Nutrition in hospitalized patients - Critical illness - Parental - Contraindic:
- Hyperosmolality.
- Severe electrolyte disturbances.
- Severe hyperglycemia.
==> Sepsis is a RELATIVE contraindic.
Nutrition in hospitalized patients - End-stage liver disease (Clin Gastro & Hep 2012) - Nutrition status …?
Predicts morbidity/mortality malnutrition in 50-90% of cirrhotics.
Nutrition in hospitalized patients - End-stage liver disease (Clin Gastro & Hep 2012) - Protein req …?
HIGHER than healthy adults (1-1.5g/kg/d vs 0.8g/kg/d).
==> Restrict ONLY if acute hep encephalopathy.
Nutrition in hospitalized patients - End-stage liver disease (Clin Gastro & Hep 2012) - Supplements:
Vit ADEK + Zinc, Selenium.
==> Do NOT carb restrict.
Nutrition in hospitalized patients - Refeeding syndrome (BMJ 2008):
Fluid/electrolyte shifts in malnourished Pts receiving artificial nutrition.
==> Hypophosphatemia is HALLMARK, but also decr. K and Mg, hyperglycemia, decr. thiamine, hypervolemia.
Nutrition in hospitalized patients - Refeeding syndrome (BMJ 2008) - Prevention:
- Thiamine 300mg PO qd.
- Vit B complex tid.
- MVI.
- Start feeding at 10kcal/kg/d (or 25% of estim goal) and incr. over 3-5days.
==> Advance only when electrolytes are w/in nl range.
==> Follow electrolytes and volume status, rehydrating and repleting.
Diverticular disease - Diverticulosis (Lancet 2004) - Definition:
Acquired herniation of colonic mucosa and submucosa through the colonic wall.
Diverticular disease - Diverticulosis (Lancet 2004) - Pathobiology - Existing dogma:
Low-fiber diet ==> Incr. stool transit time and decr. stool volume ==> Incr. intraluminal pressure ==> Herniation where vasa recta penetrate, but now ?’d (Gastro 2012).
Diverticular disease - Diverticulosis - Epidemiology:
Prevalence higher w/ incr. age (10% if <40y; 50-66% if >80y).
==> “Westernized” societies.
==> Left side (90%, mostly sigmoid) > Right side of colon (EXCEPT in Asia, where R>L).
Diverticular disease - Diverticulosis - Clinical manifestations:
- Usually asx, but 5-15% develop diverticular hemorrhage and <5% diverticulitis.
- Nuts, etc. intake in asx diverticulosis does NOT incr. risk of diverticulitis (JAMA 2008).
Diverticulitis - Pathophysio (NEJM 2007):
Retention of undigested food and bacteria in diverticulum ==> Fecalith formation ==> Obstruction ==> Compromise of diverticulum’s blood supply, infection, perforation.
Diverticulitis - Pathophysio (NEJM 2007) - Uncomplicates and complicated:
Uncomplicated ==> Microperforation ==> Localized infection.
Complicated (25%) ==> Macroperforation ==> Abscess, peritonitis, fistula (65% w/ bladder), obstruction, stricture.
Diverticulitis - Clinical manifestations:
LLQ abd pain, fever, N/V, constipation.
Diverticulitis - PEx:
Ranges from LLQ tenderness +/- palpable mass to peritoneal signs and septic shock.
Diverticulitis - Ddx:
- IBD.
- Infectious colitis.
- PID.
- Tubal pregnancy.
- Cystitis.
- CRC.
Diverticulitis - Diagnostic studies:
- Plain abd radiographs to r/o free air, ileus or obstruction.
- Abdominal CT (I+O+): >95% Se and Sp ==> Assess complicated disease (abscess, fistula).
- Colono contraindicated acutely ==> Incr. risk of perforation ==> Do 6wk after to r/o neoplasm.
Diverticulitis - Tx (Am J Gastro 2008) - Mild:
OutPt Rx indicated if Pt has few comorbidities and can tolerate POs.
==> PO abx: (MNZ + FQ) or amox/clav for 7-10d.
==> Liquid diet until clinical improvement, though recent evidence suggest abx may be unnecessary (Br J Surg 2012).
Diverticulitis - Tx (Am J Gastro 2008) - Severe:
- InPt Rx if cannot take POs.
- Narcotics needed for pain, or complications.
- NPO, IV fluids, NGT (if ileus).
- IV abx (GNR and anaerobic coverage): amp/gent/MNZ or pip/taz.
Diverticulitis - Tx (Am J Gastro 2008) - Abscess:
> 4cm should be drained percutaneously or surgically.
Diverticulitis - Tx (Am J Gastro 2008) - Surgery:
If progression despite med Rx, undrainable abscess, free perforation or possibly recurrent disease (>2severe episodes).
Diverticulitis - Tx (Am J Gastro 2008) - Colonic stricture:
Late complication of diverticulitis.
==> Rx w/ endoscopic dilation vs. resection.
==> Colono after 6wk to exclude neoplasm.
Diverticulitis - Prevention:
- LOW-fiber diet immediately after acute episode.
- HIGH fiber diet when >6wk w/o sx.
==> Consider mesalamine +/- rifaximin if multiple episodes.
Diverticulitis - Risk fo recurrence:
10-30% w/in 10y of 1st episode.
==> More likely 2nd episode complicated.
Diverticular hemorrhage - Pathophysio:
Intimal thickening and medial thinning of vasa recta as they course over dome of diverticulum ==> weaking of vascular wall ==> Arterial rupture.
Diverticular hemorrhage - Diverticular hemorrhage:
Diverticula MORE COMMON in left colon.
==> But BLEEDING diverticula more often in RIGHT colon.
Diverticular hemorrhage - Clinical manifestations:
- Painless hematochezia/ BRBPR; can have abdominal cramping.
- Usually stops spontaneously (-75%) but resolution may occur over hrs-days. 20% recur.
Diverticular hemorrhage - Diagnostic studies:
- Colono ==> Rapid prep w/ PEG-based solution via NGT.
2. Arteriography +/- tagged RBC scan if severe bleeding.
Diverticular hemorrhage - Tx:
- Colono: epinephrine inj +/- electrocautery (NEJM 2000), hemoclip, banding.
- Arteriography: Intra-arterial vasopressin infusion or embolization.
- Surgery: If above modalities fail and bleeding is persistent and hemodynamically significant.
IBD - Definition:
UC ==> Idiopathic inflammation of the colonic MUCOSA.
CD ==> Idiopathic TRANSMURAL inflammation of the GI tract, skip areas.
Indeterminate colitis ==> In 5-10% of chronic colitis, cannot distinguish UC vs CD even w/ bx.
IBD - Epidemiology and pathophysiology (NEJM 2009, Gastro 2011):
- 1.4million people in US.
- Prev 1/1000 UC and 1/3000 CD.
- Incr. incidence in Caucasians, Jews.
- Age of onset 15-30y in UC and CD; CD is BIMODAL and has a 2nd peak at 50-70y.
- Smokers incr. risk for CD, whereas nonsmokers + former smokers at incr. risk for UC.
Genetic predisposition + disruption of intestinal barrier (epithelial or decr. defenses) +/- Δ in gut microbiota ==> Acute inflam w/o immune downregulation or tolerance ==> Chronic inflam.
UC (NEJM 2011, Lancet 2012) - Clinical manifestations:
- Grossly bloody diarrhea, lower abd cramps, urgency, tenesmus.
- Severe colitis (15%).
- Extracolonic manifestations (>25%).
UC (NEJM 2011, Lancet 2012) - Clinical manifestations - Severe colitis (15%):
- Progresses rapidly over 1-2wk with decr. Ht.
- Incr. ESR.
- Fever.
- Hypotension.
- > 6 bloody BMs per day.
- Distended abdomen with absent bowel sounds.
UC (NEJM 2011, Lancet 2012) - Clinical manifestations - Extracolonic (>25%):
- Erythema nodosum.
- Pyoderma gangrenosum.
- Aphthous ulcers.
- Uveitis.
- Episcleritis.
- Thromboembolic events. (esp. during a flare; Lancet 2010).
- AIHA.
- Seroneg arthritis.
- Chronic hep.
- Cirrhosis.
- PSC (incr. risk for cholangio CA, CRC).